Vanguard TV3

NSSDC ID: VAGT3

Description

Vanguard TV3 was the first U.S. attempt to launch a satellite into orbit around the Earth. It was a small satellite designed to test the launch capabilities of a three-stage launch vehicle and study the effects of the environment on
a satellite and its systems in Earth orbit. It also was to be used to obtain
geodetic measurements through orbit analysis.

At launch the booster ignited and began to rise but about 2 seconds after liftoff, after rising about four feet, the rocket lost thrust and began to settle back down to the launch pad. As it settled against the launch pad
the fuel tanks ruptured and exploded, destroying the rocket and severely
damaging the launch pad. The Vanguard satellite was thrown clear and
landed on the ground a short distance away with its transmitters still
sending out a beacon signal. The satellite was damaged, however, and
could not be reused. It is now on display at the Smithsonian Air and
Space Museum.

The exact cause of the accident was never determined, presumably it was
due to a fuel leak between the fuel tank and the rocket engine, possibly
due to a loose connection in a fuel line or low fuel tank pressure
allowing some of the burning fuel in the thrust chamber to leak back
into the fuel tank.

Spacecraft and Subsystems

The spacecraft was a 1.36-kg aluminum sphere 15.2 cm in diameter, nearly identical to the later Vanguard 1. It contained a 10-mW, 108-MHz mercury-battery powered transmitter and a 5-mW, 108.03-MHz transmitter powered by six solar cells mounted on the body of the satellite. Six short aerials protruded from the sphere. The transmitters were used primarily for engineering and tracking data, but were also used to determine the total electron content between the satellite and ground stations. Vanguard also carried two thermistors to measure the interior temperatures in order to track the effectiveness of the
thermal protection.